No sane person would ever admit they judge an operating system by its screenshots.

Screenshots

All In One

This screenshot captures some of the most prominent HelenOS features, such as a compositing GUI with its capability to display overlapping, transparent and rotated windows, support for sound, IPv4 and IPv6 networking, multitude of file systems, and a 64-bit multithreaded, multiprocessor kernel. The picture shown by the viewer application is called ​Colorful Prague and is a courtesy of ​Miroslav Petrasko. The large yellow building with red roof and about a dozen chimneys touching the left border is the ​School of Computer Science of the ​Faculty of Mathematics and Physics, ​Charles University in Prague. That building could tell stories about the history of HelenOS.